IMSCREWS 5/16 x 3-1/2 Hex Head Lag Screws, 304 Stainless Steel, Partially Threaded Heavy-Duty Structural Framing Bolts, 20 pcs

"IMSCREWS 5/16 x 3-1/2 Heavy-Duty Lag Screws - 304 Stainless Steel (20 pcs)

Extreme Reach for Structural Framing
Our 20-piece pro-pack is designed for deep-core anchoring in heavy-duty projects. These 3.5-inch bolts provide the necessary penetration for securing thick timber rails to 4x4 or 6x6 posts. The 5/16 diameter offers professional-grade shear resistance for safety-critical outdoor structures.

Vise-Like Clamping Power
Our partially threaded shank features a smooth upper section that pulls the outer board tightly against the support beam. This clamping effect creates a gap-free, rock-solid joint, eliminating the bridging effect common in extra-long full-thread screws for a professional-grade finish.

304 Stainless Weather Protection
Forged from premium 18-8 (304) stainless steel for superior rust resistance. compatible with ACQ pressure-treated lumber. Prevents unsightly rust streaks on high-value cedar, redwood, or premium deck framing even in humid or coastal environments.

FAQ
• Tools: Fits a standard 1/2 hex socket or wrench.
• Pre-drilling: Mandatory for this length. Use a 3/16 bit for softwoods or 7/32 bit for hardwoods to prevent timber splitting.
• Why 20 pcs? The ideal bulk quantity for consistent, multi-point structural installations such as full deck railing systems or retaining walls.

Specs:
- Size: 5/16 x 3-1/2
- Thread: Partially Threaded (Max Clamping)
- Material: 304 Stainless Steel
- Drive: 1/2 Hex Head
- Qty: 20 pcs"

Key Features

• ENGINEERED CLAMPING POWER Features a partial thread that allows the smooth shank to bypass the outer member, pulling thick timber together for a gap-free, rock-solid joint.
• DEEP-ANCHOR STABILITY The 3.5-inch length is optimized for securing 2x lumber (1.5 thick) to structural posts, providing elite withdrawal resistance with 2 of deep-core thread engagement.
• 304 EXTERIOR DEFENSE Forged from premium 304 (18-8) stainless steel to prevent rust and staining in cedar, redwood, or ACQ pressure-treated lumber.
• HIGH-TORQUE DRIVE Precision hex head ensuring a secure 1/2 socket fit, providing stable torque transfer for controlled seating in dense structural timber.
• TECHNICAL SPECIFICATION To prevent splitting and protect the 5/16 shaft, pre-drilling a pilot hole (7/32 for softwoods, 1/4 for hardwoods) is mandatory for structural safety.

Specifications

• ASIN: B0F2195FPF
• Internal SKU: IMS0647
• Size: 5/16" x 3-1/2"
• Material: Stainless Steel
• Finish: Stainless Steel
• Head Style: Hex
• Package Quantity: 20